Our brains are composed of two types of tissues: gray matter and white matter. These tissues are essentially the building blocks of the parts of our brain which provide function to our bodies and house the mysterious consciousness which makes us unique. While both tissues are different from each other and are considered separate entities, they actually require each other's presence for the body to thrive.
Gray matter consists mainly of nerve cell bodies, synapses, capillaries, and branching dendrites. While gray matter only makes up 40% of brain tissue, it is involved in all muscle control and sensory perception. On the other hand, white matter takes the other 60% to use for passing messages throughout the central nervous system. The tissues work together to keep the body functioning in an orderly fashion. However, brain damage can impact these functions, hindering the ability of the human mind and body.
So how is the brain tissue damaged and how severe can the damage be?
Brain damage can happen to either white matter or gray matter. Depending on which one is damaged, the effects can be different.
White matter injuries happen when the messaging tracts are damaged causing communication between gray and white matter to be very limited. A common example of white matter damage is a spinal cord injury. The outer part of a spinal cord is comprised of large white matter tracts which, when transected or compressed, can lead to paralysis. This is because the brain's gray matter can no longer reach the spinal cord which means no signals can be passed through the nervous system.
White matter injuries can be very serious but, depending on how bad the injury was and the type of injury, recovery can occur. However, gray matter injuries can be more serious.
When gray matter is injured, it can commonly be associated with neuronal death. The cell bodies are responsible for keeping the neurons alive using up a lot of oxygen and energy. Therefore, conditions such as hypoxia (when the brain doesn't have enough oxygen to function properly) can cause injury to gray matter, leading to neuronal death. Physical damage from accidents is also responsible for neuron death. Unlike white matter, gray matter cannot repair or recreate damaged or dead cells, making them of greater risk and significance.